1. Field of the Invention
The present invention relates to a capacitive touch pad apparatus. More particularly, the present invention relates to a capacitive touch pad apparatus for sensing a finger contact with an insulating sheet covering an electrode by noticing a change in capacitance between the electrode and the finger.
2. Description of the Related Art
According to one example of this type of an apparatus, a plurality of switch electrodes are placed on a panel and are further covered by a glass plate (or an acrylic plate). When a finger of an operator contacts the glass plate, a capacitance of a switch electrode positioned on a bottom side of a contact portion increases. A manner of manipulating on the panel is determined by noticing such a change in capacitance, and a process depending upon a determination result is executed by a CPU.
However, in the above-described apparatus, a lead pattern connected to a switch electrode is formed near another switch electrode. Thus, a contact by the finger of an operator increases a capacitance of the lead pattern, and there is a possibility that the manner of manipulating may be erroneously determined.